Indigoid dyestuffs and process of making same



Patented Apr. 22, 1930 UNITED STATES PATENT OFFICE ROBERT STOCKER, OF BASEL, SWITZERLAND, ASSIGNOR TO SOCIETY CHEMICAL INDUSTRY IN BASLE, OF BASEL, SWITZERLAND INDIGOID DYESTUFFS AND PROCESS OF MAKING SAME 1T0 Drawing. Application filed July 7, 1926, Serial No. 121,055, and in Switzerland July 29, 1925.

The present invention relates to new indigoid dyestuffs obtainable from chlorotoluidine (CH :NH :Cl=1:2:6 which are valuable for the production of fast tints. It

' 5 comprises the process of making the new dyestuffs, the dyestuffs themselves, and the material dyed with the new dyestufl. It has been found that new indigoid dyestuffs may be obtained as follows In a first step chloro-o-toluidine by treatment with saponifying agents, such as solutions of caustic alkalis.

In a third step the named chlorothiocresol is converted into the 2-methyl-3-chlorophenylthioglycollic acid by condensation with a mono-halogen-acetic acid.

In a fourth step the 2-methyl-3-chlorophenylthioglycollic acid is condensed by means of halides of inorganic hydroxy acids,

as for instance phosphorous trichloride, and

condensing agents, to the corresponding 6- chloro 7-methyl-3-hydroxythionaphthene.

In a fifth step the 6-chloro-7-methyl-3- hydroxythionaphthene is first treated with aromatic nitroso compounds, as for instance p-nitrosodimethylaniline or p-nitrosophenol, to form an anil of the 6-chloro-7-methylo thionaphthenequinone, and then converted by treatment with saponifying agents, as for example dilute sulfuric acid, into 6-chloro- 7 -methyl-thionaphthenequinone.

In a sixth step the products which may be obtained by the processes of the fourth and fifth step, and which correspond with the general formula:

wherein it stands for a reactive group such as O, anil or 2H, are condensed with compounds of the general formula wherein 3 represents a reactive group, such as O, halogen, anil, 2H, and m, n and 0* atoms of which two are carbon atoms adjacent to each other, which at the same time appertain to an aromatic ring system, and of which the third is NH, S or C.

Such compounds are for instance fivemembered condensed ring s stems, as for example isatins, indoxyls, thlonaphthenequinones, hydroxythionaphthenes, naphthohydroxythlophenes, acenaphthenequinones and the like, their homologues and substitution products, anils and halides,

This reaction takes place by heating the components in a solvent which may act as condensing agent, in certain cases by fiddltion of oxidizing agents.

The dyestuffs thus obtained correspond with the general formula wherein 1', m and n have the signification as has hereinbefore been defined. They form orange to red, violet and brown powders, which dissolve in concentrated sulfuric acid to violet to brown, green and yellowish-green solutions, yielding with hydrosulfite and caustic soda solution greenish-yellow to yellow and violet vats which dye cotton fast orange to red, violet, brown and grey tints.

These dyestuffs may further be converted into dyestuffs containing more halogen by subsequent halogenation.

The following examples, illustrate the invention, but without limiting it, the parts being by weight.

Example 1 71 parts of 6-chloro-ortho-toluidine (CH NI-I (ll-=1: 2:6)

are dia-zotized in known manner and the mixture is introduced into a solution of 90 parts of potassium Xanthate and 80 parts of soda ash at C. When evolution of gas has come to an end the mixture is allowed to cool and extracted with ether. The ether is evaporated and the residue, which consists very probably of the Xanthic acid chlorotolylester of the formula is saponified by heating it in a reflux apparatus with 125 parts of caustic soda solution of 40 B. and 300 parts of alcohol, and in the same solution the product is condensed with 70 parts of chloroacetic acid, dissolved in 84 parts of caustic soda solution of 40 B. and water. The spirit is distilled and the residue allowed to cool and acidified with hydrochloric acid. The 2-methyl-3-chlorophenylthioglycollic acid corresponding with the formula is filtered and dried. When recrystallized from dilute alcohol it forms white needles, which melt at 104 C.

28 parts of this product are dissolved in 280 parts of phosphorus trichloride, 22 parts of aluminium chloride are added and the whole is heated gradually to 60-65 C. Hydrogen chloride is evolved freely and the liquid assumes a red brown color. The excess of phosphorus trichloride is distilled in a-vacuum and the residue introduced into a mixture of ice and water for the purpose of decomposing the compounds of phosphorus and aluminium; After filtering the product is dissolved in dilute caustic soda solution and the solution is filtered and acidifiedto precipitate the product.

The 6-chloro'-7-methyl-3-hydroxythionaphthene corresponding with the formula CH1 6/ H 0 is a colorless substance which crystallizes from dilute acetic acid in'beautiful needles melting at 102103 C. It is sparingly soluble in alcohol, ether, ligroin and benzene. It can easily be purified by distillation with steam.

E azample 2 dissolves in hot benzene to a red solution and crystallizes on cooling in beautiful needles of green lustre and melting point 256-257 C.

WVhen 34.9 parts of the compound are introduced into 300 parts of sulfuric acid of 60 B. and heated cautiously to 60 C. whilst stirring, the color of the mass becomes brown-red and there is precipitated in good yield 6-chloro-7-methyl-thionaphthenequ.inone. This is filtered, washed until free from acid and crystallized from benzene. The new thioisatin thus obtained corresponding with the formula forms brown-red needles of melting point 154C.

Ewample 19.8 parts of 6-chloro-7-n'1ethyl-3-hydroxythionaphthene are dissolved in 1000 parts of caustic soda solution of 2 per cent strength and air is blown through the solution at (SO-70 (1., until the quantity of the dyestuif produced does not increase. This new 6: 6'- dichloro-7 7-dimethylthioindigo of the formula is filtered, washed free from alkali and dried. It is a Carmine-red powder which dissolves in sulfuric acid to a yellowish-green solution.

It dyes cotton in a greenish-yellow hydrosulfite vat bright Carmine-red tints of pronounced fastness to washing and chlorine.

E mample 4 305 parts of 5 7-dibron1isatin are suspended in 3000 parts of chlorobenzene and the mixture is heated after addition of 229 parts of phosphorus pentachloride. The solution of 5:7 -dibromisatinchloride thus obtained is allowed to flow at a temperature of -80 0., and whilst stirring, into a solution of 198 parts of 6-chloro-7-methyl-3-hydroxythionaphthene in 2000 parts of chlorobenzene, whereby the dyestufl corresponding with the formula is immediately precipitated. It is filtered, washed and dried. It is a violet powder which dissolves in sulfuric acid to a green solution and forms a golden-yellow vat and dyes cotton violet tints of very good fastness.

E mample 5 which separates in good yield is filtered, washed and dried. It is an orange powder, soluble in sulfuric acid to a bright green solution. It forms a violet-red vat and dyes cotton pure orange tints of very good fastness.

Example 6 198 parts of 6-chloro-'l-methyl-3-hydroxythionaphthene' and 330 parts of the paradimethylaminoanil of 5 chloro 7 methyl-- thionaphthenequinone are suspended in 4000 parts of benzene and the suspension is heated to boiling. The condensation is complete after a short boiling. The dyestuff corresponding with the formula CH3 I II r,

separates in good yield and is filtered and dried. It forms a Carmine-red powder soluble in sulfuric acid to a yellowishgreen solution. It forms a pale yellow vat and dyes cotton bluish-rose tints of very good fastness.

The same dyestuif is produced by condensing 6-chloro 7 methyl-thionaphthenequinone para dimethyl aminoanil or 6- chloro-7-methyl-thionaphthenequinone with 5 chloro -7-methyl-3-hydroxythionaphthene.

In an analogous manner a dyestuff of a redder shade is obtained by replacing the para-dimethylaminoanil of the 5-chloro-7- methylthionaphthenequinone by the corresponding anil of the 6-chloro-4-methylthionaphthenequinone. The para-dimethylaminoanil of 6-ethoxythionaphthenequinone leads to a dyestuff of more scarlet shade.

Example '7 198 parts of 6-chloro-7-1nethyl-3-hydroxythionaphthene and 332 parts of the paradimethylaminoanil of 2:3-thionaphthisatin (B B -naphththiofurane-l-: 'Q-dione) are suspended in 4000 parts of benzene. The condensation is finished after a short boiling. The dyestuif corresponding with the formula 0 o II H o 0 which separates in good yield is filtered and dried. It is a violet-grey powder which dissolves in sulfuric acid to a green solution. It forms a golden yellow vat and dyes cotton grey-blue tints.

Example 8 new dyestufi' and is a violet-brown powder, soluble in sulfuric acid to a green solution. The dyestufi' forms a yellow-orange vat and dyes cotton pure violet tints of pronounced fastness; A similar productis obtained by chlorinating the dyestuff of Example 7.

The following table comprises further examples of dyestuffs obtainable from 6-chloro- 7-methyl-3-hydroxythionaphthene in accordance with the invention.

according to the process of claim 1, with alkalies.

3. As a step in the manufacture of new indigoid dyestuffs obtainable from chlorotoluidine (CH :NI-I :Cl=1:2:6), the herein described production of the 2-methyl-3- chlorophenylthioglycollic acid, by treatment of the chlorothiocresol (CH :SI-I :Cl= 1 :2 :6) with a salt of a monohalogeno-acetic acid.

4. As a step in the manufacture of new 6-chloro-7-methyl-S-hydroxythionaphthene audggg gg gfg gfg g ggf g 'j g f I 5-bromo-2:l-thionaphthisatin (fi-bromo-fli,m-naphththiofurane-1z2-dione) Brown Violet Orange-brown Brown. II 1:2-thionaphthisatin(a ,B -naphththiofurane-1:2-dione). Brown Green Golden-yellow". Bordeaux-rod. II1 a-isatinanilide Violet Green Pale yello\v Violct. IV 5:7-dibl0misatin .a Brown Brown Orange-brown Red-brown. V Pera-dimetliylaminoanil of thionaphthenequinone Brown (lrcen Pale yellow Red. VI Para-dimethylaminoanil -of 6-chlorothionaphthenequinone Red-hrown Green Yellow Red. VII l-chloro-2:3-thi0naphthisatiu (l-chlorofihfiz-naphththim furane-l:2-di0ne) Violet-l'cd Green; Orange Violet.

The dyestuft' No. II corresponds with the indigoid dyestuffs obtainable from chloroformula: toluidine (CH :NII :Cl=1:2:6), the here- CH 1n described production of the 6-chloro-7- S methyl-3-hydroxythionaphthene, by treat- 01 ment of the 2-methyl-3-chlorophenylth1o- I glycoll c acid with a halide of an morgamc o hydroxy acid and wlth a condensing agent.

ll 3 5. As a step in the manufacture of new The dyestufi No. IV corresponds with the formula:

The dyestuff No. VII

corresponds with the formula \Vhat I claim is:

1. As astep in the manufacture of new indigoid dyestuffs obtainable from chlorotoluidine (CI-I :NH :Cl=1:2:6), the herein described process consisting in the manufacture of xanthic acid chlorotolylester, by diazotizing the above named chlorotoluidine, and treating the diazo compound thus obtainled with an alkali metal salt of Xanthic acic.

2. As a step in the manufacture of new indigoid dyestuffs obtainable from chlorotoluidine (CH,,:NH :Cl=l:2 :6), the herein described production of the chlorothiocresol (CH SI-I:Cl=l 2:6), by treatment of the Xanthic acid chlorotolylester, obtained indigoid dyestuffs obtainable from chlorotoluidine ((lI-I zNl-I z Cl=1 :2 6), the herein described production of the anils of the 6-chloro-7-methylthionaphthenequinone, by treating the 6-chloro-7-methyl-3-hydroxythionaphthene with an aromatic nitroso compound, and saponifying the anil thus obtained.

6. As a step in the manufacture of new indigoid dyestuffs obtainable from chlorotoluidine (CH :NH :Cl=1:2:6), the herein described condensation of the products corresponding with the general formula and of which the third is NH, C or S.

7. The manufacture of new indigoid dyestufis obtainable from chlorotoluidine (CH :NH Cl=1:2:6), by diazotizing, in a first step, the above named ehlorotoluidine and treating the diazo-compound thus obtained with an alkali metal salt of Xanthic acid, by treating, in a second step, the Xanthic acid chlorotolylester thus obtained with alkalies, by treating, in a third step, the chlorothiocresol (CH :SH:Gl=1:2:6)

thus obtained with a salt of a mono-halogenoacetic acid, by treating, in a fourth step, the 2 methyl 3 chlorophenylthioglycollic acid thus obtained with a halide of an inorganic hydroxy acid and a condensing agent, by treating, in a fifth step, the 6-chloro-7-methyl- 3-hydroxythionaphthene thus obtained with products corresponding with the general formula 7p'C=O wherein 1", n and on stand for atoms of which two are carbon atoms adjacent to each other, which at the same time appertain to an aromatic ring system, and of which the third is N H, S or C, which products form orange to red, violet and brown powders, which dissolve in concentrated sulfuric acid to violet to brown, green, and yellowish-green solutions, yielding with hydrosulfite and caustic soda solution greenish-yellow to yellow and violet vats which dye cotton fast orange to red, violet, brown and grey tints.

9. As new products of manufacture the herein described new indigoid dyestuffs of the general formula two are carbon atoms adjacent to each other, which at the same time appertain to an aromatic ring system of the benzene series, and of which the third is NH, S or C, which products form orange to red and brown powders, which dissolve in concentrated sulfuric acid to brown to green and yellowish-green solutions, yielding with hydrosulfite and caustic soda solution greenish-yellow to yellow and violet vats, which dye cotton fast orange to red, violet and brown tints. v

10. As new products of manufacture the herein described new indigoid dyestufis of the general formula wherein 7" represents S or NH, and in which I the two carbon atoms 0 and C appertain to an aromatic ring system of the benzene series, which products dissolve in concentrated sulfuric acid to brown, green and yellowishgreen solutions, yielding with hydrosulfite and caustic soda solution yellow to greenishyellow vats, which dye cotton fast red to violet and brown tints.

11. As new products of manufacture the herein described indigoid dyestuffs of the general formula wherein the twocarbon atoms 0 and C appertain to an aromatic ring system of the benzene series, which products form red to carmine and violet powders, which dissolve in concentrated sulfuric acid to green solutions, yielding with hydrosiilfite and caustic soda solution yellow to green vats which dye cotton fast red to rose and violet tints.

. 12. As new products of manufacture the herein described new indigoid dyestuffs of the formula which form red to carmine-red products, dissolving in concentrated sulfuric acid to green solutions, yielding with hydrosulfite and caustic soda solution yellow to greenish-yellow vats which dye cotton fast bluish-red to rose tints.

1;;3. Material dyed with the products 0 claim 8.

14. Material dyed with the products of claim 9.

15. Material dyed with the products of claim 10.

16. Material dyed with the products of claim 11.

17 Material dyed with the products of claim 12.

In witness whereof I have hereunto sign-ed my name this 22nd day of June, 1926.

- ROBERT STOOKER. 

